Calculation And Optimization Analysis Of Shafting Transverse Vibration Performance Taking Into Account The Alignment Parameters

Propulsion shafting is the core component of Marine power system.Shafting alignment scheme is the theoretical basis of shafting alignment and installation.Poor alignment of shafting may cause accidents such as excessive vibration or bearing high temperature alarm during self-navigation.The research shows that the influence of reasonable alignment design scheme on lubrication characteristics and vibration performance is not clear.Therefore,it is difficult to control it from a single performance design.Obviously,the shipboard shafting alignment,lubrication and vibration performance are coupled with each other,while the traditional rational alignment is only optimized from a single characteristic,so it is difficult to obtain the optimization results under the action of multi-performance coupling.Based on the coupling relationship between alignment,lubrication and lateral vibration of shafting,a multi-performance coupling design optimization model of shafting was established in this paper.Specific work contents are as follows:Firstly,the coupling relationship between alignment parameters and lubrication performance is studied and analyzed.It is found that alignment parameters have a great influence on the lubrication characteristics of bearings.Then,based on the alignment calculation theory and considering the influence of lubrication characteristics on the alignment state of shafting,the dynamic alignment method of shafting taking into account the lubrication characteristics of liquid film was introduced,and the coupling relationship between the characteristics of liquid film and the alignment performance was discussed.Then,the coupling calculation model of shaft alignment,bearing lubrication and lateral vibration of shaft system was established based on the supporting stiffness obtained by dynamic alignment calculation including the coupling of liquid film dynamic characteristics as the connection.The natural characteristics of lateral vibration and the variation of forced vibration response characteristics of shaft system under different alignment schemes were analyzed.At the same time,the interval characteristics of displacement frequency response function of each bearing were studied based on Monte Carlo method to verify the feasibility and rationality of controlling vibration response of shafting system by adjusting bearing displacement.Based on the above research,a multi-performance coupling design optimization model of shafting alignment,lubrication and lateral vibration was established.Then,the multi-objective grey Wolf optimization algorithm,which does not require function gradient and continuous differentiability,is used as the optimizer to solve the multiobjective optimization model of shafting system.Finally,the fuzzy comprehensive evaluation method was used to evaluate the Pareto solution set,and the alignment scheme was obtained,which satisfied the optimal combination of the alignment performance and the transverse vibration performance of the shaft and ensured the good dynamic pressure lubrication performance.